Thwarted clumsy fraudster pocketing wallet, ultimately (10)
I believe the answer is:
frustrated
'thwarted' is the definition.
('frustrate' can be a synonym of 'thwart')
'clumsy fraudster pocketing wallet ultimately' is the wordplay.
'clumsy' indicates an anagram.
'pocketing' is an insertion indicator.
'ultimately' suggests the final letters.
The last letter of 'wallet' is 't'.
'fraudster' with letters rearranged gives 'frustraed'.
'frustraed' enclosing 't' is 'FRUSTRATED'.
(Other definitions for frustrated that I've seen before include "Thwarted" , "Foiled" , "Prevented from progressing" , "Disheartened" , "Disappointingly unsuccessful" .)